Typically outdoor lighting provided for public places, such as for towns, cities or districts thereof are operated by light sensor based or clock/timer based control systems for switching the lights on or off. Such an arrangement may involve issuing control signals e.g. via dedicated control cables or by employing power-line communication (PLC) techniques to one or more relays in a lightning cabinet, which relays in turn pass the operating power to one or more lights sources accordingly. Such systems typically only allow switching the light sources on or off but do not provide e.g. dimming capabilities.
Recently, two types of systems that also allow dimming have been provided. Simple ones are capable of dimming down the light sources for a predetermined period(s) of time within a lighting period, which lighting period typically covers the night time. A shortcoming of such systems is that ballasts and/or driver apparatuses employed therein do not offer any flexibility or possibilities for adjusting the dimming characteristics. Consequently, the energy consumption of such a lighting system may be unnecessarily high and/or the provided lighting level cannot be tailored to meet the required characteristics.
More advanced systems may allow control of lighting by a PLC technique, via a wireless connection or by employing dedicated control cables. While such systems may provide rather versatile possibilities for controlling dimming (and other) behavior of lighting, on the other hand in many cases they provide a level of sophistication greatly exceeding that required for control of lighting of public places and hence incur unnecessarily high costs and possibly also reliability problems.